Add performance counters to measure current connections by transport
Keep previous logic for updating ConnectionsCurrent PerfCounter.
Merge branch 'dev' of https://github.com/SignalR/SignalR into dev
Re-add connection counter methods for longPolling transport (merge conflict resolved)
Fix summary comments and descriptions in PerformanceCounterManager.
Merge pull request #2971 from thomaswr/dev

Add performance counters to measure current connections by transport